1. Field
The present disclosure relates to a system and a method for resolution conversion of textual content or Magnetic Ink Character Recognition (MICR) content in an image.
2. Description of Related Art
In image printing systems (e.g., inkjet image printing systems), there is a need to have different resolutions for different primary ink colors. This is a problem for most Page Description Language (PDL) imaging technologies because they render each primary ink color at the same resolution. Common interpolation methods from one resolution to another resolution do not produce optimal output at the new resolution.
One example where this is a problem is high resolution text printing in which a higher resolution is used for printing text so as to improve rendering of small text. As text is most often rendered using black color ink, black color image plane can be imaged at a higher resolution than the image planes of the other primary ink colors.
Another example where this is a problem is MICR printing using different heads or different print stations at different resolutions for printing the MICR ink.
MICR technology is generally well-known. MICR inks contain a magnetic pigment or a magnetic component in an amount sufficient to generate a magnetic signal strong enough to be readable via a MICR reader device. Generally, the ink is used to print all or a portion of a document, such as checks, bonds, security cards, etc. For example, most checks exhibit an identification code area, usually at the bottom of the check. The characters of this identification code are usually MICR encoded. The document may be printed with a combination of MICR-readable ink and non-MICR-readable ink, or with just MICR-readable ink. The document thus printed is then exposed to an appropriate source or field of magnetization, at which time the magnetic particles become aligned as they accept and retain a magnetic signal. The document can then be read by passing it through a reader device, which detects or “reads” the magnetic signal of the MICR imprinted characters. MICR readers have strict tolerances on character shape and the resulting signal strength.
The architecture of continuous feed (CF) direct marking (DM) printing systems includes the use of multiple print heads (or marking stations) distributed into several color print head modules along the printing path. These multiple print heads are distributed over a long print zone to print the desired image. An exemplary continuous feed printing system may have as many as six color modules with four print units per color module incorporating fourteen print heads. Also, the continuous feed printing system prints on a band, a web or a roll of paper/media as compared to a sheet printing system which prints on discrete sheets of media.
In one MICR implementation for the continuous feed printing system, a set of aqueous ink print heads are added to an otherwise solid inkjet printing engine having solid inkjet print heads. The aqueous ink print head technology can be different from the solid inkjet print head technology. For example, the solid inkjet print heads may be clocked at a fixed frequency no matter how fast the web moves while the MICR print heads are clocked at a rate proportional to the web speed. In another example, the solid inkjet print heads may be manufactured with a different number of nozzles per inch than the MICR print heads. Due to these differences in the print head technologies involved, the aqueous ink print heads operate at a different resolution than that of the solid inkjet print heads. Additionally, for each unique web speed, images printed with the solid inkjet print heads change resolution but those printed with the aqueous ink print heads do not. The web speed, as used herein, refers to the speed at which a roll (or a web) of media (or paper) is being fed into a continuous feed printing system.